[Bugfix] Infinite loop fix in ArangoD AsyncClient (#1049)

Author: ajanikow

CHANGELOG.md

@@ -29,6 +29,7 @@
 - (Bugfix) Allow to remove resources (CPU & Memory) on the managed pods
 - (Bugfix) Add DistributeShardsLike support
 - (Feature) Member restarts metric
+- (Bugfix) Infinite loop fix in ArangoD AsyncClient
 
 ## [1.2.13](https://github.com/arangodb/kube-arangodb/tree/1.2.13) (2022-06-07)
 - (Bugfix) Fix arangosync members state inspection

pkg/util/arangod/conn/async_errors.go

@@ -35,7 +35,7 @@ func IsAsyncErrorNotFound(err error) bool {
 		return true
 	}
 
-	return IsAsyncErrorNotFound(errors.Cause(err))
+	return IsAsyncErrorNotFound(errors.CauseWithNil(err))
 }
 
 func newAsyncErrorNotFound(id string) error {
@@ -61,7 +61,7 @@ func IsAsyncJobInProgress(err error) (string, bool) {
 		return v.jobID, true
 	}
 
-	return IsAsyncJobInProgress(errors.Cause(err))
+	return IsAsyncJobInProgress(errors.CauseWithNil(err))
 }
 
 func newAsyncJobInProgress(id string) error {

pkg/util/arangod/conn/async_errors_test.go

@@ -0,0 +1,37 @@
+//
+// DISCLAIMER
+//
+// Copyright 2016-2022 ArangoDB GmbH, Cologne, Germany
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Copyright holder is ArangoDB GmbH, Cologne, Germany
+//
+
+package conn
+
+import (
+	"testing"
+
+	"github.com/arangodb/kube-arangodb/pkg/util/errors"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_IsAsyncErrorNotFound_Loop(t *testing.T) {
+	require.False(t, IsAsyncErrorNotFound(errors.Newf("Error")))
+}
+
+func Test_IsAsyncJobInProgress_Loop(t *testing.T) {
+	_, ok := IsAsyncJobInProgress(errors.Newf("Error"))
+	require.False(t, ok)
+}

pkg/util/errors/errors.go

@@ -45,6 +45,20 @@ var (
 	WithMessagef = errs.WithMessagef
 )
 
+// CauseWithNil returns Cause of an error.
+// If error returned by Cause is same (no Causer interface implemented), function will return nil instead
+func CauseWithNil(err error) error {
+	if nerr := Cause(err); err == nil {
+		return nil
+	} else if nerr == err {
+		// Cause returns same error if error object does not implement Causer interface
+		// To prevent infinite loops in usage CauseWithNil will return nil in this case
+		return nil
+	} else {
+		return nerr
+	}
+}
+
 func Newf(format string, args ...interface{}) error {
 	return New(fmt.Sprintf(format, args...))
 }